AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  Purple service app for multi-bus, multi-account-pattern

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Globals:
  Function:
    Timeout: 3
    Handler: app.lambda_handler
    Runtime: python3.9
    Tags:
      pattern: multi-bus-multi-account-pattern

Parameters:
  EventBusName:
    Description: Name of the purple service app event bus
    Type: String
    Default: purple-service-event-bus-multi-bus

  BlueServiceAccountNo:
    Description: Account Id Blue service event bus to add rules
    Type: String

  OrangeServiceAccountNo:
    Description: Account Id Orange service event bus to add rules
    Type: String

Resources:

  # Event bus for purple service.
  PurpleServiceEventBus: 
    Type: AWS::Events::EventBus
    Properties: 
        Name: !Ref EventBusName
      
  # Resource policy for Purple service event bus
  PurpleServicePublishStatement:
    Type: AWS::Events::EventBusPolicy
    Properties:
      EventBusName: !Ref PurpleServiceEventBus
      StatementId: "PurpleServicePublish"
      Statement:
        Effect: "Allow"
        Principal:
          AWS: 
            - !Sub arn:aws:iam::${AWS::AccountId}:root
        Action: "events:PutEvents"
        Resource: !GetAtt PurpleServiceEventBus.Arn
        Condition:
          StringEquals:
            "events:source": ["com.exampleCorp.PurpleService"]

  PurpleEventBusRuleCreationStatement:
    Type: AWS::Events::EventBusPolicy
    Properties:
      EventBusName: !Ref PurpleServiceEventBus
      StatementId: "AllServiceRuleCreation"
      Statement:
        Effect: "Allow"
        Principal:
          AWS: 
            - !Sub arn:aws:iam::${BlueServiceAccountNo}:root
            - !Sub arn:aws:iam::${OrangeServiceAccountNo}:root
        Action:
          - "events:PutRule"
          - "events:DeleteRule"
          - "events:DescribeRule"
          - "events:DisableRule"
          - "events:EnableRule"
          - "events:PutTargets"
          - "events:RemoveTargets"
        Resource:
          - !Sub arn:aws:events:${AWS::Region}:${AWS::AccountId}:rule/${PurpleServiceEventBus.Name}/*
        Condition:
          StringEqualsIfExists:
            "events:creatorAccount": "${aws:PrincipalAccount}"
            "events:source": "com.exampleCorp.PurpleService"

  PurpleServicePublisherE2:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: purple_p_e2/
      Policies:
        - Version: '2012-10-17' 
          Statement:
            - Effect: Allow
              Action:
                - events:PutEvents
              Resource: "*" 
      Environment:
        Variables:
          EVENT_BUS_ARN: !Ref PurpleServiceEventBus

  PurpleServiceSubscriberE1:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: purple_s_e1/
      Events:
        PurpleE1Rule:
          Type: EventBridgeRule
          Properties:
            EventBusName: !Ref PurpleServiceEventBus
            Pattern:
              source:
                - com.exampleCorp.BlueService
              detail-type:
                - Event1

  PurpleServiceSubscriberE3:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: purple_s_e3/
      Events:
        PurpleE3Rule:
          Type: EventBridgeRule
          Properties:
            EventBusName: !Ref PurpleServiceEventBus
            Pattern:
              source:
                - com.exampleCorp.OrangeService
              detail-type:
                - Event3

  # Purple service event bus targe DLQ 
  PurpleServiceEventBusDlq:
    Type: AWS::SQS::Queue


Outputs:
  PurpleServiceEventBusArn:
    Description: The ARN of the Purple event bus
    Value: !GetAtt PurpleServiceEventBus.Arn
  PurpleServicePublisherE2:
    Description: Lambda function name for purple service publishing event 2
    Value: !Ref PurpleServicePublisherE2
  PurpleServiceSubscriberE1:
    Description: Lambda function name for purple service subscriber to event 1
    Value: !Ref PurpleServiceSubscriberE1
  PurpleServiceSubscriberE3:
    Description: Lambda function name for purple service subscriber to event 3
    Value: !Ref PurpleServiceSubscriberE3
  PurpleServiceEventBusDlqUrl:
    Description: URL of the SQS Queue for rules DeadLetterConfig
    Value: !Ref PurpleServiceEventBusDlq
  PurpleServiceEventBusDlqArn:
    Description: ARN of the SQS Queue for rules DeadLetterConfig
    Value: !GetAtt PurpleServiceEventBusDlq.Arn